Eyre Peninsula, SA, 1953 (P109), magnetic line data, AWAGS levelled

Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. These line dataset from the Eyre Peninsula, SA, 1953 survey were acquired in 1953 by the SA Government, and consisted of 9840 line-kilometres of data at 1600m line spacing and 175m terrain clearance. To constrain long wavelengths in the data, an independent data set, the Australia-wide Airborne Geophysical Survey (AWAGS) airborne magnetic data, was used to control the base levels of the survey data. This survey data is essentially levelled to AWAGS.总磁强度（Total Magnetic Intensity, TMI）数据用于量化地壳内造岩矿物成分差异所引发的地球磁场强度变化。磁异常可分为正异常（磁场强度高于正常值）与负异常（磁场强度低于正常值），其类型取决于岩石的磁化率。该数据通过标准处理流程开展预处理，以确保记录的磁场响应仅源于地下岩石的影响。经处理得到的数据集可通过地质解译，揭示地下地质构造。GA的地球物理学家会对处理后的数据进行质量核查，以确保GA发布的最终数据符合使用要求。这批测线数据集源自1953年南澳大利亚州（SA）政府在艾尔半岛（Eyre Peninsula）开展的航空磁测，测线总长9840线千米，线间距为1600米，飞行离地高度为175米。为压制数据中的长波长信号，研究人员采用全国尺度航空地球物理调查（Australia-wide Airborne Geophysical Survey, AWAGS）的航空磁测数据作为参考基准，对本次测线数据的基准面进行校正。本次测线数据实质上已基于AWAGS数据完成平差校正。